In a suspension apparatus of a vehicle, for example, an upper link and a lower link are controlled to protrude or to retract by an actuator, thereby restraining variations in camber angle and tread of a wheel caused by bumping and rebounding in order to enhance steering stability performance (see, e.g., JP 6-047388 B2). The actuator includes a motor and a feed screw mechanism in which a male screw member is relatively rotated with respect to a female screw member by the motor.
The actuator is configured as a single assembly including the motor and the feed screw mechanism. Thus, when partially changing a specification of the motor or the feed screw mechanism, it is necessary to redesign the overall structure the actuator. Accordingly, versatility with respect to various models is low so that cost is high.